I retested the different scenarios, it seems to be working for the Application that was increased in the Major Version but not for Application that was only increased in the Minor Version. The WSDL will always belongs to the oldest version of the deployed Application of the same Major Version No.

Yup, till now still encounting this issue. I believe even in LiveCycle ES (v8.2) you will also faced the same issue.

If this is a big issue to you, you can try creating your new application by increasing only the major version instead of minor version. You will be able to retrieve the correct WSDL if all your application version is only different in its major version numeber.